/* This header file is part of the ATMEL AVR32-SoftwareFramework-1.2.2ES-AT32UC3A Release */

/*This file has been prepared for Doxygen automatic documentation generation.*/
/*! \file *********************************************************************
 *
 * \brief Cycle counter driver.
 *
 * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
 * - Supported devices:  All AVR32UC devices.
 * - AppNote:
 *
 * \author               Atmel Corporation: http://www.atmel.com \n
 *                       Support and FAQ: http://support.atmel.no/
 *
 *****************************************************************************/

/* Copyright (c) 2007, Atmel Corporation All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. The name of ATMEL may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ATMEL ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND
 * SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#ifndef _CYCLE_COUNTER_H_
#define _CYCLE_COUNTER_H_

#include "compiler.h"


//! Structure holding private information, automatically initialized by the 
//! cpu_set_timeout() and cpu_is_timeout() functions.
typedef struct
{
  //! Holds the timeout information.
  unsigned long time;

  //! Tells if the CPU counter shall wrap (TRUE) or not (FALSE) before the timeout detection.
  Bool wrap;
} t_cpu_time;


/*!
 * \brief Convert milli-seconds into CPU cycles.
 *
 * \param  ms:      Number of millisecond.
 * \param  fcpu_hz: CPU frequency in Hz.
 *
 * \return the converted number of CPU cycles.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ U32 cpu_ms_2_cy(unsigned long ms, unsigned long fcpu_hz)
{
  return ((unsigned long long)ms * fcpu_hz + 999) / 1000;
}


/*!
 * \brief Convert CPU cycles into milli-seconds.
 *
 * \param  cy:      Number of CPU cycles.
 * \param  fcpu_hz: CPU frequency in Hz.
 *
 * \return the converted number of milli-second.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ U32 cpu_cy_2_ms(unsigned long cy, unsigned long fcpu_hz)
{
  return ((unsigned long long)cy * 1000 + fcpu_hz-1) / fcpu_hz;
}


/*!
 * \brief Convert CPU cycles into micro-seconds.
 *
 * \param  cy:      Number of CPU cycles.
 * \param  fcpu_hz: CPU frequency in Hz.
 *
 * \return the converted number of micro-second.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ U32 cpu_cy_2_us(unsigned long cy, unsigned long fcpu_hz)
{
  return ((unsigned long long)cy * 1000000 + fcpu_hz-1) / fcpu_hz;
}


/*!
 * \brief Set a timer variable.
 *
 * Ex:  t_cpu_time timer; 
 *      cpu_set_timeout( cpu_ms_2_cy(10, FOSC0), &timer ); // timeout in 10 ms  
 *      if( cpu_is_timeout(&timer) )
 *        ../..
 *
 * \param  delay:   (input) delay in CPU cycles before timeout.
 * \param  cpu_time: (output) internal information used by the timer API.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ void cpu_set_timeout(unsigned long delay, t_cpu_time *cpu_time)
{
  // Use the CPU cycle counter.
  unsigned long delay_start_cycle = Get_system_register(AVR32_COUNT);
  unsigned long delay_end_cycle   = delay_start_cycle + delay;

  if (delay_start_cycle <= delay_end_cycle)
    cpu_time->wrap=FALSE;
  else
    cpu_time->wrap=TRUE;

  cpu_time->time= delay_end_cycle;
}


/*!
 * \brief Test if a timer variable reached its timeout.
 *
 * Ex:  t_cpu_time timer; 
 *      cpu_set_timeout( 10, FOSC0, &timer ); // timeout in 10 ms  
 *      if( cpu_is_timeout(&timer) )
 *        ../..
 *
 * \param  cpu_time:   (input) internal information used by the timer API.
 *
 * \return TRUE if timeout occured, otherwise FALSE.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ unsigned long cpu_is_timeout(t_cpu_time *cpu_time)
{
  unsigned long delay_end_cycle = cpu_time->time;
  // Use the CPU cycle counter.
  if (cpu_time->wrap==FALSE)
  {
    if( (unsigned long)Get_system_register(AVR32_COUNT) < delay_end_cycle )
      return FALSE;
    else
      return TRUE;
  }
  else
  {
    if( (unsigned long)Get_system_register(AVR32_COUNT) > delay_end_cycle )
      return FALSE;
    else
    { // AVR32 counter has wrapped.
      cpu_time->wrap=FALSE;
      return FALSE;
    }
  }
}


/*!
 * \brief Waits during at least the specified delay (in millisecond) before returning.
 *
 * \param  delay:   Number of millisecond to wait.
 * \param  fcpu_hz: CPU frequency in Hz.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ void cpu_delay_ms(unsigned long delay, unsigned long fcpu_hz)
{
  t_cpu_time timer;
  cpu_set_timeout( cpu_ms_2_cy(delay, fcpu_hz), &timer);
  while( !cpu_is_timeout(&timer) );
}


/*!
 * \brief Waits during at least the specified delay (in CPU cycles) before returning.
 *
 * \param  delay:   Number of CPU cycles to wait.
 * \param  fcpu_hz: CPU frequency in Hz.
 */
#if __GNUC__
__attribute__((__always_inline__))
#endif
extern __inline__ void cpu_delay_cy(unsigned long delay, unsigned long fcpu_hz)
{
  t_cpu_time timer;
  cpu_set_timeout( delay, &timer);
  while( !cpu_is_timeout(&timer) );
}


#define Get_sys_count()     ( Get_system_register(AVR32_COUNT)        )
#define Set_sys_count(x)    ( Set_system_register(AVR32_COUNT,   (x)) )
#define Get_sys_compare()   ( Get_system_register(AVR32_COMPARE)      )
#define Set_sys_compare(x)  ( Set_system_register(AVR32_COMPARE, (x)) )


#endif // _CYCLE_COUNTER_H_
